Develop Reference

Java - JFrame break Components like FlowLayout, but order them vertically

since some hours I am trying to create a JFrame whit following behavior:
I have a Title (with maybe an Image included) -This is centered at the top. -> Check
The rest of this JFrame should be filled with JPanel.
The first JPanel should be placed in the center on top. The second JPanel should be placed under the first and so on. When the first JPanel runs out of the screen, a second row needs to be created.
I dont care if they are reordered or not. Here is a drawing i prepared to show what I want:
Example - I need one of that behaviors
I have tried out so many combination of different Layouts.. But still can't find the right solution.
Here is my code, which is working fine besides the fact, that my panels are ordered from left to right instead of from top to down.. :(
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class myFrameClass extends JFrame {
myFrameClass() {
super();
setLayout(new BorderLayout());
GraphicsDevice[] gs = GraphicsEnvironment.getLocalGraphicsEnvironment().getScreenDevices();
GraphicsConfiguration[] gc = gs[0].getConfigurations();
setUndecorated(true);
setBackground(Color.WHITE);
setLocation(gc[0].getBounds().x, gc[0].getBounds().y);
setExtendedState(JFrame.MAXIMIZED_BOTH);
add(getHeader(), BorderLayout.NORTH);
add(getPanels());
setVisible(true);
}
private JPanel getPanels() {
JPanel p = new JPanel();
p.setLayout(new FlowLayout());
int cnt = 6;
for (int i = 0; i < cnt; i++) {
p.add(getPanel());
}
return p;
}
private JPanel getPanel() {
JPanel p = new JPanel();
p.setBackground(Color.RED);
p.setPreferredSize(new Dimension(200, 200));
return p;
}
private JPanel getHeader() {
JPanel p = new JPanel();
p.add(new JLabel("Titel"));
return p;
}
public static void main(String args[]) {
new myFrameClass();
}
}
I also found Oracle VerticalFlowLayout but was not able to access it. Might it help me? In case - how to use it?
Otherwise.. How to use JFrame to archive that behavior?
Thank you

Java dynamically changing components when scrollbar appears

I'm trying to implement a feature that (in my test project) once a button is pressed, it adds a random number to my JPanel. (I use the layouts I have because in my real program, I have more items inside and it displays correctly). But I need my program to recognize when the scrollbar is visible (which I implemented that, but it's a little delay. What I mean by delay is I push the button to add a number, if the scrollbar becomes visible nothing happens. But then the next time I press the button it shifts over like I want). The other problem I have (the one I'm focused on now) is that when I dynamically change the size of the JPanel, if the scrollbar is visible, I have it set to change the width to my width - the width of the scrollbar. But It seems like when the scrollbar is visible, the newly inputted number moves over twice the scrollbar width instead of just once. I've been at this part of my program for over a day and can't figure it out. I'll add my full code and some screenshots.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Main {
JFrame frame;
JPanel topPanel;
JPanel memoryPanel;
JScrollPane sPane;
JButton button;
ArrayList<Integer> list = new ArrayList<>();
boolean isVScrollVisible = false;
int scrollBarSize = 0;
public class MyChangeListener implements ChangeListener {
#Override
public void stateChanged(ChangeEvent e) {
isVScrollVisible = (sPane.getVerticalScrollBar().isVisible());
}
}
public class ButtonListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
Random random = new Random();
int r = random.nextInt(10);
list.add(r);
int n;
if (isVScrollVisible) {
n = scrollBarSize;
} else {
n = 0;
}
JPanel nextPanel = new JPanel();
nextPanel.setName("" + r);
nextPanel.setForeground(Color.BLACK);
nextPanel.setPreferredSize(new Dimension(200 - n, 55));
nextPanel.setMinimumSize(new Dimension(200 - n, 55));
nextPanel.setMaximumSize(new Dimension(200 - n, 55));
JPanel labelPanel = new JPanel();
labelPanel.setLayout(new BorderLayout());
JLabel label = new JLabel();
label.setText("" + r);
label.setPreferredSize(new Dimension(200 - n, 55));
label.setMinimumSize(new Dimension(200 - n, 55));
label.setMaximumSize(new Dimension(200 - n, 55));
label.setHorizontalAlignment(JLabel.RIGHT);
label.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 17));
label.setFont(new Font("Sans-Serif", Font.BOLD, 20));
labelPanel.add(label);
nextPanel.add(labelPanel, BorderLayout.LINE_START);
for (int i = 0; i < memoryPanel.getComponents().length; i++) {
memoryPanel.getComponent(i).setPreferredSize(new Dimension(200 - n, 55));
memoryPanel.getComponent(i).revalidate();
memoryPanel.getComponent(i).repaint();
}
memoryPanel.add(nextPanel, 0);
memoryPanel.revalidate();
memoryPanel.repaint();
sPane.revalidate();
sPane.repaint();
}
}
public Main() {
frame = new JFrame();
topPanel = new JPanel();
memoryPanel = new JPanel();
memoryPanel.setLayout(new BoxLayout(memoryPanel, BoxLayout.Y_AXIS));
sPane = new JScrollPane(memoryPanel, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
sPane.setPreferredSize(new Dimension(200, 300));
sPane.getViewport().addChangeListener(new MyChangeListener());
scrollBarSize = ((Integer)UIManager.get("ScrollBar.width")) + 1;
button = new JButton("Add Random Number");
button.addActionListener(new ButtonListener());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
topPanel.add(button);
frame.add(topPanel, BorderLayout.PAGE_START);
frame.add(sPane, BorderLayout.CENTER);
frame.setResizable(false);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
new Main();
}
}
I need them to look exactly the same. Before I had the code I have now, the scrollbar would appear over the numbers which looked ugly. And the reason I have the frame resizable false is because In my real program I hard coded all the sizes, which in the future I will calculate the correct sizes based on the size of the frame, so right now setting resizable to true is out of the question. Any suggestions on what to do?
This is what I'm trying to accompolish.

Get rid of all the logic that sets the preferred/minimum/maximum sizes. Each component knows what its size should be. Each layout manager will in turn know what the preferred size of the panel should be. Let the layout manager use the information to do its job.
The basic logic for dynamically adding components is:
panel.add(...);
panel.revalidate();
panel.repaint();
Then the scrollbars will appear automatically when required. There is no need for listeners or anything.
Edit:
The reason I set all the sizes is because If I take them out then everything appears centered
Learn how to use layout managers properly and effectively.
For example when using a BoxLayout you can control the alignment of components by using:
component.setAlignmentX(JLabel.RIGHT_ALIGNMENT);
and the component will be aligned to the right edge of the space available to the component.
When using a JLabel you may also need to set a property on the JLabel to align the text to the right edge of the label. Read the JLabel API for the appropriate method.

I'm making a Java interactive novel, but my JTextArea Disappears

My adventure game has a bunch of nested if statements to output something based on the input, but my JTextField only gets one input and then disappears. I want to get the JTextField to take unlimited inputs and use .append to to show them in the jtextarea. I want to have the program continue to take user inputs until the story path in the if statements end. If want to get input from a JTextField and put the output in the JTextArea and keep it there.
import java.awt.Dimension;
import java.awt.Font;
import java.awt.KeyboardFocusManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.IOException;
import java.util.Scanner;
import java.io.Reader;
import javax.swing.*;
import javax.swing.text.BadLocationException;
/*JakeBarcelona
*Date:May 5, 2016
*Program Name:StoryTester.java
*Description:
*/
public class StoryTester extends JFrame
{
static JTextField input = new JTextField(30);
static JTextArea fields = new JTextArea(30,50);
static Story ARoom=new Story();
public static void main(String[] args) throws BadLocationException
{
JFrame frame = new JFrame();
String story=new String();
JLabel intro = new JLabel(story);
//Sets the JLabels font and color
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//puts a red x to close it
Story wow = new Story();
String introduction=wow.intro();
//creates array field for text editing
fields.insert(introduction, 0);
String name= fields.getText(0,30);
//creates new Panel
JPanel myPanel=new JPanel();
//creates label for text box
myPanel.setPreferredSize(new Dimension(600,600));
myPanel.add(fields);
myPanel.add(input);
//puts a scroll bar and cancel and ok button
JScrollPane scroll = new JScrollPane(fields, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
myPanel.add(scroll);
int result = JOptionPane.showConfirmDialog(null, myPanel, "Story", JOptionPane.OK_CANCEL_OPTION);
if(result==JOptionPane.OK_OPTION);
{
String jake = input.getText();
String need = ARoom.storyStatements(jake);
System.out.println(need);
fields.append(need);
}
}
}

You are adding fields twice to the GUI, once to myPanel and once to the JScdrollPane, scrool, which is then added to myPanel. Don't do this, but rather add it to the JScrollPane only. You're also artificially constraining the size of your myPanel JPanel, and this is likely what's getting you into trouble.
Instead use layouts in a smart way by for instance giving myPanel a BorderLayout, adding the JScrollPane to the BorderLayout.CENTER position and the inputs JTextField to the BorderLayout.PAGE_END position. And don't set the preferred size of myPanel but rather let the text component column and row properties set their preferred size which will in turn set the preferred size of the myPanel JPanel.
Also you're using static fields inappropriately and in fact none of your current fields should be static.
For example
import java.awt.BorderLayout;
import javax.swing.*;
public class LayoutEg extends JPanel {
private static final int COLS = 50;
private static final int ROWS = 30;
private JTextField input = new JTextField(COLS);
private JTextArea fields = new JTextArea(ROWS, COLS);
public LayoutEg() {
// two methods below so that words wrap
fields.setWrapStyleWord(true);
fields.setLineWrap(true);
fields.setFocusable(false); // so we can't write directly into JTextArea
JScrollPane scrollPane = new JScrollPane(fields);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
setBorder(BorderFactory.createEmptyBorder(2, 2, 2, 2));
setLayout(new BorderLayout(2, 2));
add(scrollPane, BorderLayout.CENTER);
add(input, BorderLayout.PAGE_END);
}
private static void createAndShowGui() {
LayoutEg mainPanel = new LayoutEg();
JFrame frame = new JFrame("Story GUI");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}

Replacing a JPanel with a different JPanel

Hi this is a bit of a basic question. In my code I create a gui in a constructor then nest a ActionListener class to handle button changes. This code will create the gui and the action listener runs through the actionPerformed method correctly. However, I've tried multiple ways to change the panel in the gui but I feel like the way I have the program set up it is not possible for this to work. Sorry if this is a repeat but after searching for a while on S.O. I haven't found a good example that would help me with my problem.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import org.math.plot.Plot2DPanel;
import org.math.plot.plotObjects.BaseLabel;
public class GraphGui extends JFrame {
//default width and height of the GUI
private static final int WIDTH = 1200;
private static final int HEIGHT = 700;
GraphPlot gp = new GraphPlot();
Plot2DPanel plotPanel =gp.determinePlotToPlot("duration");
/**
* This is the constructor that initializes the JFrame and the layout of the GUI.
* The radio buttons are also created here and grouped accordingly.
*/
public GraphGui() {
//title of GUI
setTitle("VibeTech Graph Gui");
//First JRadioButton for date vs duration
JRadioButton durToDate = new JRadioButton("Duration vs. Date");
durToDate.addActionListener(new RadioButtonListener());
durToDate.setActionCommand("duration");
durToDate.setSelected(true);
//JRadioButton for weight vs date
JRadioButton weightToDate = new JRadioButton("Weight vs. Date");
weightToDate.addActionListener(new RadioButtonListener());
weightToDate.setActionCommand("weight");
//JRadioButton for plan type vs date
JRadioButton planToDate = new JRadioButton("Plan vs. Date");
planToDate.addActionListener(new RadioButtonListener());
planToDate.setActionCommand("level");
//button group of the buttons to display them as one group
ButtonGroup group = new ButtonGroup();
group.add(planToDate);
group.add(weightToDate);
group.add(durToDate);
//create JPanel to add objects to
JPanel jplRadio = new JPanel();
jplRadio.setLayout(new GridLayout(0, 1));
//add radio buttons
jplRadio.add(planToDate);
jplRadio.add(weightToDate);
jplRadio.add(durToDate);
Plot2DPanel dvt = new Plot2DPanel();
dvt.addLinePlot("Duration over Time", gp.getDate(), gp.getDuration());
BaseLabel title = new BaseLabel("Duration over Time", Color.RED,
0.5, 1.1);
title.setFont(new Font("Courier", Font.BOLD, 20));
dvt.addPlotable(title);
dvt.setAxisLabels("Time", "Duration");
setLayout(new BorderLayout());
add(jplRadio, BorderLayout.WEST);
add(plotPanel, BorderLayout.EAST);
setSize(WIDTH, HEIGHT);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
//main method to run program
public static void main(String [ ] args)
{
//create new GUI
#SuppressWarnings("unused")
GraphGui test = new GraphGui();
}
//create a radio button listener to switch graphs on button press
class RadioButtonListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
if(e.getActionCommand().equals("duration")) {
plotPanel = gp.determinePlotToPlot("duration");
} else if (e.getActionCommand().equals("weight")) {
plotPanel = gp.determinePlotToPlot("weight");
} else if (e.getActionCommand().equals("level")) {
plotPanel = gp.determinePlotToPlot("level");
}
//here is where I tried to do removes, adds, and validates but
//I have trouble getting to the frame itself to remove the JPanel
//component. I think this is a setup problem.
}
}
}

You would need to add the panel and revalidate/repaint the JFrame for it to appear:
add(plotPanel, BorderLayout.EAST);
revalidate();
repaint();
Better to use CardLayout to manage this type of functionality.

Try using CardLayout for switching between panels. Here is my solution for a similar question: https://stackoverflow.com/a/9377623/544983

Understanding layout managers -- I'm not, please enlighten me

I'm just not understanding why things are being resized when I call the validate() and repaint() methods. I'm struggling to understand this. Essentially, my program is meant to display like this. I have a main frame into which I plug the various JPanels that I'm extending for the various functions of my photo album. The class below is the NewAlbum class that is supposed to allow the user to select files and make a new album out of them.
The code for choosing files works nicely. Once the files are selected, the change to the NewAlbum panel should be the select files button is replaced by a done button. Under the done button is a JSplitPane with the horizontal splitter just off center with the right side being larger than the left. The left side will eventually have a thumbnail of each photo as metadata about the photo is entered into the right side.
The right side pane is to be a JScrollPane with a single JPanel which has, in a grid form, the 4 entries that the user is asked for data about. After adding everything, the dimensions are where I want them to be, but when I call the validate/repaint combination the dimensions become "messed up." I'm pretty sure it's because I'm not understanding how the default layout managers for the various classes I'm using, or extending. Please help me understand. Also, tell me if the GridBagLayout is what I want, or if a different one is what I'm looking for.
The NewAlbum code is below.
I apologize for the uncompilable code. I figured that you'd be able to just look at the class and tell me, "Oh, yeah, this is the problem." Below is compilable and does demonstrate the problem. Once the files are selected, the split pane window is too thin and too long. I want it to fit inside the frame. Actually, it should fit inside the JPanel which is inside the JFrame.
Thanks,
Andy
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.Iterator;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
class Main extends JFrame {
static JPanel transientPanel = null;
public Main() {
super();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(640, 480);
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("Example");
JMenuItem albumMenu = new JMenuItem("New Album");
albumMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
transientPanel = new NewAlbum();
add(transientPanel);
validate();
repaint();
}
});
menu.add(albumMenu);
menuBar.add(menu);
setJMenuBar(menuBar);
validate();
}
public static void main(String[] args) {
final Main m = new Main();
m.setVisible(true);
}
}
/**
* #description NewAlbum is the window that is presented to the user
* to select new photographs for the album. Once selected, the user
* will be presented a form, of sorts, to complete the metadata for this
* album.
* #author Andy
*/
class NewAlbum extends JPanel {
JButton selectFiles;
JButton done;
JButton nextButton = new JButton("Next Image");
ArrayList<File> filesArray;
JSplitPane splitWindow = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, true);
JScrollPane scrollWindow;
JPanel rightSidePanel = new JPanel();
JPanel leftSidePanel = new JPanel();
JLabel subjectLabel = new JLabel("Image subject:");
JLabel locationLabel = new JLabel("Image location:");
JLabel commentLabel = new JLabel("Comments:");
JLabel dateLabel = new JLabel("Date (mm/dd/yyyy):");
JTextField subjectText = new JTextField(25);
JTextField locationText = new JTextField(25);
JTextArea commentText = new JTextArea(4, 25);
JTextField dateText = new JTextField(10);
public NewAlbum() {
super();
selectFiles = new JButton("Select Photos");
selectFiles.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
selectFilesForAlbum();
}
});
add(selectFiles);
}
private void configureRightPanel() {
int jPanelX = getParent().getWidth();
int jPanelY = getParent().getHeight() - 30; // this should account for buttons
// now, resize this panel so that it will be the right size for the split pane
jPanelX = jPanelX - (int)(jPanelX * .31);
rightSidePanel.setSize(jPanelX, jPanelY);
rightSidePanel.add(subjectLabel);
rightSidePanel.add(subjectText);
rightSidePanel.add(locationLabel);
rightSidePanel.add(locationText);
rightSidePanel.add(commentLabel);
rightSidePanel.add(commentText);
rightSidePanel.add(dateLabel);
rightSidePanel.add(dateText);
rightSidePanel.add(nextButton);
// iterate over the photos selected, make bogus info for now
}
private ArrayList<File> makeFileIntoArrayList(File[] f) {
ArrayList<File> a = new ArrayList<File>();
a.addAll(Arrays.asList(f));
return filesArray = a;
}
/**
* selectFilesForAlbum
* This method is private to the NewAlbum class. It is the handler for
* when the user clicks on the "select photos" button. When the function
* executes, it displays the JFileChooser so that the user may select
* the desired photos. The files selected are assigned to a class variable
* of type File[] which is used by the enterPhotoInfo method.
*
* #return void
*/
private void selectFilesForAlbum() {
JFileChooser jfc = new JFileChooser();
jfc.setMultiSelectionEnabled(true);
jfc.showOpenDialog(this);
makeFileIntoArrayList(jfc.getSelectedFiles());
changeButtonToDone();
enterPhotoInfo();
// TODO write the photo album to the disk
}
private void changeButtonToDone() {
remove(selectFiles);
done = new JButton("Done");
add(done);
// by the time this gets called, we'll have a parent container
getParent().validate();
getParent().repaint();
}
private void enterPhotoInfo() {
splitWindow.setSize(this.getWidth(), this.getHeight() - 30);
// remove when the left side panel actually has something
Dimension iewDims = splitWindow.getSize();
int leftX = iewDims.width - (int)(iewDims.width * .69);
int leftY = iewDims.height;
leftSidePanel.setSize(leftX, leftY);
configureRightPanel();
scrollWindow = new JScrollPane(rightSidePanel);
scrollWindow.setSize(rightSidePanel.getSize());
splitWindow.setRightComponent(scrollWindow);
splitWindow.setLeftComponent(leftSidePanel);
splitWindow.setDividerLocation(.31);
System.out.println("Printing dimensions of before validate/repaint: this, splitWindow, scrollWindow, LSP, RSP");
debugPrintDimensions(this);
debugPrintDimensions(splitWindow);
debugPrintDimensions(scrollWindow);
debugPrintDimensions(leftSidePanel);
debugPrintDimensions(rightSidePanel);
//infoEntryWindow.add(infoScroller);
this.add(splitWindow);
this.validate();
this.repaint();
System.out.println("Printing dimensions of: this, splitWindow, scrollWindow, LSP, RSP");
debugPrintDimensions(this);
debugPrintDimensions(splitWindow);
debugPrintDimensions(scrollWindow);
debugPrintDimensions(leftSidePanel);
debugPrintDimensions(rightSidePanel);
}
private void debugPrintDimensions(Container c) {
System.out.println("DEBUG: Containers (x,y): (" +
String.valueOf(c.getWidth()) +
"," +
String.valueOf(c.getHeight()) +
")");
}
}

Also, tell me if the GridBagLayout is what I want, or if a different one is what I'm looking for.
You use the appropriate layout manager for the job. This can also mean using different layout managers on different panels.
splitWindow.setSize(this.getWidth(), this.getHeight() - 30);
You should NEVER use setSize(). That is the job of the layout manager, to determine the size of the component based on the rules of the layout manager.
All components have a preferred size which is used by the layout manager. At times you can use the setPreferredSize() to change the default.

By selecting a LayoutManager, you are handing over control of the layout to that layout manager. You can give the LayoutManager hints via layout constraints and restrictions by setting the preferred dimensions on the components you are arranging, but essentially, the layout manager will call the shots.
With GridBagLayoutManager you can achieve almost anything with constraints and component dimension settings, but it can still be tricky to get right. Try setting the preferred size on your components.
I used to use GridBagLayoutManager for everything, but then I came across MigLayout which really is a huge step forward in terms of easy configuration and layout consistency. I recommend you give it a look.